I purchased a new dado set so I could work on my beehive project. So far I’ve only made enough box joints with the set to make 6 hives and it is so dull it’s almost unusable. Is this normal? It’s a $100 Diablo set cutting pine.

15 replies so far

Cutting pine, the first thing I would check for is pitch on the blades. I would take them off and clean them. You can buy a chemical spray to clean pitch off of blades. It burns my skin. I use WD-40, let it soak and if it needs it I brush it a little with a brass bristle brush. Cleans stuff right up. Wipe it off, reinstall it and you should be good to go.

I use both the Rockler product and oven cleaner. Both work well. I tend to like the oven cleaner better since I just spray it on and put the blade outside for 10 to 15 minutes (a good excuse to spend some time in the shop) and rinse it off. Dry the blade with shop towels.

But to answer your question I don’t believe that the dado set should be dull yet. I have a Forrest dado set that I bought 5 years ago and it is still sharp despite a lot of use since I do all my rabbeting and dadoing on the ts.

-- Challenges are what make life interesting; overcoming them is what makes life meaningful- Joshua Marine

Something else is wrong here, that’s really not enough cutting to get pitch build up unless you’re using green wood. This may sound idiotic but check to make sure the blade is mounted so the blade is rotating in the proper direction. I made the mistake of putting a wobble dado (not a word about my wobble dado LJ’s) on with the teeth facing the wrong direction. Got alot of burning and difficult cutting to say the least. IF there is visible pitch build up there are any number of products to remove it. Cheap alternative is denatured alcohol or acetone. Steel mum is right wrap in paper towels and let is soak and use a brass brush.

-- Common sense is so rare anymore when you do see it, it looks like pure genius.

If the blades are the right way and the blades are clean, it is possible that the blades are dull. This can happen if you’re trying to cut too deeply and your tablesaw doesn’t have the power to support the cut. Did you get a lot of burning? The heat will make the blades dull more quickly.Try taking less out with each pass if this is the case.

Also make sure the outside blades are mounted properly, I had a couple of projects where the bottom edges of my dados had ramps. If you are cutting through real pitchy material see above about cleaning but I like to use Krud Kutter, you can get it a the orange Box. Make sure that no matter what you use you give it a good rinse with water an dry it (I like to use my airhose.

-- //FC - Round Rock, TX - "Experience is what you get just after you need it"

Thanks for all the info guys. But do you think I’m dumb enough to put the blades on backwards? Well, OK, I am dumb enough. I did it a couple weeks ago. Took me a while to figure out why it was cutting poorly and making a lot of smoke. Unfortunately, that wasn’t the case this time. After last time (I do learn sometimes ;)), that was the first thing I checked.

I used acetone and a brass brush, because that’s what I happened to have on hand. Made a big difference. Not like new, but much better.

I’ve been using Krud Kutter to clean my blades. It’s a liquid concentrate used with pressure washers. Just a couple of caps full with some hot water and let the blades soak for a few hours. Brush off with a nylon brush, rinse and they’re like new.-JJ